Oral hygiene compositions suitable for use as dentifrice compositions such as toothpastes, and mouthwashes are well known. Modern dentifrices often contain an abrasive substance for the controlled mechanical cleaning and polishing of teeth, and optionally a number of other common ingredients, including humectants, binders, flavours, colours, therapeutic or active ingredients, such as a fluoride source, rheology control agents, preservatives, and foaming agents or detergents.
The primary function of the abrasive substance in such dentifrice formulations is to help remove various deposits, including pellicle film, from the surface of the teeth. Pellicle film adheres tightly to the teeth and often contains coloured constituents, which impart an unsightly appearance.
An effective dentifrice formulation should seek to maximise the removal of various deposits, including pellicle film. The abrasive used in such formulations is preferably selected so as not to damage gums, nor the hard tissues of teeth through abrasion or demineralisation of the hard teeth tissue. The abrasiveness of toothpastes results from abrasives such as silica, calcium phosphate, alumina or other solid particles in the toothpaste mechanically removing deposits and films from the teeth.
There is a continued need for alternative abrasives for use in dentifrice formulations such as toothpastes, which provide the necessary cleaning requirements, including pellicle film removal, and/or tartar inhibition combined with acceptable or improved levels of abrasiveness. Achieving this balance has hitherto proved challenging.
The present invention is based on the finding that silicon, and in particular porous silicon, may be used as an abrasive agent in oral hygiene compositions including those suitable for use as dentifrice compositions.